Video Editing PC repairs & computer upgrades

ZEN has been involved with micro-computers since about 1980 (!)

Since then we've used a variety of systems and
kept track of key developments along the way. However, the fundamental
building blocks are the same.

Here's a guide to some of the key components in any PC system

The CPU - the main powerhouse of any PC

The CPU (Central Processing Unit) is the core
component which determines the processing speed of your computer. Whilst
other components (eg Storage disks and memory chips) can affect the speed of
certain operations (like copying files), processes that involve complex
calculations (like rendering effects and encoding video) will generally
depend on the clock speed and performance of the CPU. In some cases these
sort of processes can be off-loaded onto the GPU (Graphics Processing Unit –
i.e. the graphics card), but only if a specific application is programmed to
use a particular type of graphics card. There is no generic way that
graphics cards can take over from the CPU, so no matter how powerful the GPU
on the card, it will only benefit those applications that know how to use
it. A faster CPU will generally benefit all applications.

The problem with upgrading the CPU is that
there have been many CPU families, even from the same manufacturer, each one
with a different connection to the motherboard (i.e. socket type), and even
within those groups that share a common socket type there are different
requirements for the supporting chipset on the motherboard. The net result
of this is that unless your CPU is one of the slowest in a compatible group,
you will not simply be able to buy a new CPU chip and swap it with the
existing one. Instead, you will also have to get a new motherboard that’s
compatible the new CPU, and possibly new RAM if the type supported by the
new board is different from that on the old one. Sometimes the graphics card
slot changes as well, but that hasn’t happened for a while, not since the
introduction of PCI-Ex to replace AGP.

RAM
- the memory chips

Upgrading the RAM capacity can improve system speed, but it’s a
popular misconception that “adding more RAM makes your system faster”. It’s
really a half-truth, incorrectly derived from the fact that “not having enough
RAM will make your system slower” (or, worse still, crash), when it has to use
the swap file on disk instead of the RAM chips. Disk access is an order of
magnitude slower than RAM access. But if you do have sufficient RAM, any
additional RAM will not be used and the system will be no faster than it was
before.

How
do you know if you have sufficient RAM? Windows has a built-in RAM monitor in
the Task Manager, accessed by pressing the Control-Alt-Delete keys. Under the
Performance tab are a selection of graphs and readings which will let you see
how much RAM is being used at any time, and (on the lower graph) how that usage
varies over time.

If you monitor the RAM usage whilst working on an application
which you think might be pushing the limits, you will be able to see whether
this is the case or not. If the RAM graph and Total used show that RAM usage is
less than the Total Physical Memory, then you don’t really need any more. Note:-
if the CPU usage is near 100%, and you are performing a CPU-intensive task like
encoding or rendering, this is a good thing. Only when you think the CPU should
be idling but you find it’s at or above 50% should you be worried, and then it’s
time to look under the Processes tab to see which Process is hogging all the CPU
resources.

Disk
Storage

Once upon a time, when non-linear editing was in its infancy,
hard disks struggled to cope with the data rates required to play full-res video
files. For reference, uncompressed 4:2:2 SD video runs at about 20MB/s
(160Mb/sec), and even high-performance hard disks of the day were hard pushed to
maintain much above 5MB/s. Even with compressed video, playing multiple streams
inevitably required RAID arrays in order to get sufficient speed. But
like other PC components, disk speeds have increased and these days any
“commodity” hard disk will easily deliver 50MB/s or more. At the same time, video
compression quality has improved such that, apart from at the very high end, most video
acquisition is done at data rates between 3-7MB/s.

If you need to increase your
overall disk storage, removable disks are an attractive option, particularly if
you need to move data between systems, but in some cases they can be slower than
internal disks. USB
is a popular option for external disks because it’s widely supported across PCs
and Macs, desktops and laptops, and be “hot-plugged”, but the original USBv1 is
not fast enough, and whilst USBv2 is generally OK, it will be the limiting
factor in transfer speed.

To get the best out of the current generation of SATA
disks, the best two connection methods are either e-SATA or the newer USBv3.
eSATA effectively connects an external SATA disk directly to an internal SATA
disk controller port, such that it runs just as fast as if it were fitted
internally. USBv3 has upped the transfer speed from USBv2 such that it currently
exceeds that of available disks, and has the twin advantages of backward
compatibility with previous USB ports (where it will simply run slower) and easy
hot-swapping. Finally, one of the most cost-effective options for removable
storage is have a front-loading SATA drive bay fitted to your PC. These allow
bare SATA drives to be easily removed and inserted whereupon they will run at
full speed alongside the other internal drives.

Graphics
Cards

It’s common knowledge that you need a good graphics card in a video
editing system, but just how good? Graphics cards can range in price from
tens of pounds to thousands of pounds, so what difference can they make? As
with many components in a PC, the answer is really software-dependant. There
are some basic functions a graphics card has to perform to support Windows
and the sort of common functions found in all Windows applications, but
beyond that it’s down to the application to unlock the additional processing
power that the graphics card processor (the GPU) might be capable of. And if
a particular function within a video application is not written to use the GPU,
then a better graphics card will provide no benefit.

...at any particular point in time, cards in the middle to upper part
of the “gaming” range offer the best value for money...

Traditionally, it’s been the video gaming industry (and high-end CAD) that
has pushed development of graphics cards, and been the only type of
application to take full advantage of GPU power, but video editing software
is beginning to catch up, and applications like
Premiere Pro (from CS5 onwards) is one such example. It
is specifically written to take advantage of certain cards with Nvidia
chipsets that will run their CUDA graphics programming language, in order
for the GPU to perform real-time video effects.

Some other editing programs make use of the more widely
supported DirectX and OpenGL graphics programming language, which opens up
the choice of cards. Generally, at any particular point in time, cards in
the middle to upper part of the “gaming” range offer the best value for
money, typically costing between 100-300 pounds. However, everything moves
on apace, and the performance and capabilities of a “higher end” card from a
few years ago are likely to be equalled or bettered by a “mid range” card of
today.

Talk to us on 0161 736 5300

I've been a regular contributor to user groups and technical forums for
the last 20 years or so, and have written hundreds of posts
on a whole range of computer, audio & video
production topics. Trouble is, I never kept copies of any of them, which
is why I've now created a web page for some of them.
e.g. - Desk Microphone - Recommendations?

Here's a check-list for recording good speech. 1) A
reasonably "dead" room, acoustically, so it doesn't sound like ...
Read More

What we're about . . .
ZEN is not a traditional Audio-Visual dealer who started selling computers,
nor is it a computer shop that also sells video products. You won't
get any salesmen giving you the "hard-sell" when you call, just
straightforward advice and information - which for some callers is the
knowledge that they don't need to buy whatever it is they thought they
needed! Above all you'll be dealing with someone with a wide range of
experience and knowledge of both PCs and video production. We're not the
biggest, nor necessarily the cheapest, but we are one of the longest
established computer/video specialists in the UK.

Company history . . .
ZEN was started in the 1980s by Martin Kay, then working for ITV at
Granada's Manchester studios, who built his first 6502-based computer in
1979 from an Ohio Scientific kit, bought in the USA whilst working as a
Sound Recordist on a
film shoot for World In Action. With the advent of the Amiga, which could be gen-locked
to a video source, Martin started writing a variety of video-related software. This
included subtitling & tele-prompting, ident clocks, scoring software for
sports & gameshows, and specialist software to mimic other computer
displays for
use in TV film dramas like Cracker, Prime Suspect and A Touch of Frost.
Martin left Granada in 1993 to concentrate on his computer-video activities
with ZEN, following a natural path into non-linear editing systems,
for many years the main business activity, although he still maintains an active
interest in video production.